On January 1, 2008, Knapp Corporation acquired machinery at a cost of $250,000. Knapp adopted the double-declining balance method of depreciation for this machinery and had been recording depreciation over an estimated useful life of ten years, with no residual value. At the beginning of 2011, a decision was made to change to the straight-line method of depreciation for the machinery. what the depreciation expense for 2011 would be ?